<template>
  <div id="nav">
  <router-view/>

  </div>
</template>
<script>
export default {
  created(){
    //在页面加载时读取sessionStorage里的状态信息
    if (sessionStorage.getItem('store')) {
      this.$store.replaceState(Object.assign({}, this.$store.state, JSON.parse(sessionStorage.getItem('store'))));
    }

    //在页面刷新时将vuex里的信息保存到sessionStorage里
    window.addEventListener('beforeunload', () => {
      sessionStorage.setItem('store', JSON.stringify(this.$store.state));
    });

  }
}
</script>
<style lang="scss">

</style>
